Fine-Mapping of IL16 Gene and Prostate Cancer Risk in African Americans
CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION
Authors: Batai, Ken; Shah, Ebony; Murphy, Adam B.; Newsome, Jennifer; Ruden, Maria; Ahaghotu, Chiledum; Kittles, Rick A.
Abstract
Background: Prostate cancer is the most common type of cancer among men in the United States, and its incidence and mortality rates are disproportionate among ethnic groups. Although genome-wide association studies of European descents have identified candidate loci associated with prostate cancer risk, including a variant in IL16, replication studies in African Americans (AA) have been inconsistent. Here we explore single-nucleotide polymorphism (SNP) variation in IL16 in AAs and test for association with prostate cancer. Methods: Association tests were conducted for 2,257 genotyped and imputed SNPs spanning IL16 in 605 AA prostate cancer cases and controls from Washington, D.C. Eleven of them were also genotyped in a replication population of 1,093 AAs from Chicago. We tested for allelic association adjusting for age, global and local West African ancestry. Results: Analyses of genotyped and imputed SNPs revealed that a cluster of IL16 SNPs were significantly associated with prostate cancer risk. The strongest association was found at rs7175701 (P = 9.8 x 10(-8)). In the Chicago population, another SNP (rs11556218) was associated with prostate cancer risk (P = 0.01). In the pooled analysis, we identified three independent loci within IL16 that were associated with prostate cancer risk. SNP expression quantitative trait loci analyses revealed that rs7175701 is predicted to influence the expression of 106 and other cancer-related genes. Conclusion: Our study provides evidence that IL16 polymorphisms play a role in prostate cancer susceptibility among AAs. Impact: Our findings are significant given that there has been limited focus on the role of IL16 genetic polymorphisms on prostate cancer risk in AAs. Cancer Epidemiol Biomarkers Prev; 21(11); 2059-68. (C)2012 AACR.
Regeneration of Sudanese maize inbred lines and open pollinated varieties
AFRICAN JOURNAL OF BIOTECHNOLOGY
Authors: Omer, Rasha Adam; Ali, Abdelbagi M.; Matheka, Jonathan M.; Machuka, Jesse
Abstract
Eight maize inbred lines and three open pollinated varieties from Sudan were evaluated for their response to tissue culture. Immature embryos obtained 16 days after pollination were used as explants for callus induction. Calli were induced on LS medium supplemented with 2 mg/L 2,4-dichlorophenoxyacetic acid. Callus induction capacity was highest in inbred lines IL3, IL15 and IL1. The Varieties Hudiba-2 and Hudiba-1 were not statistically different (p > 0.05) in callus induction. The capacity for embryogenic callus formation was highest in inbred line IL3 followed by IL1 and IL38 and in varieties Hudiba-2 and Hudiba-1. Inbred lines IL16, IL42, IL43 and IL28 had the lowest embryogenic callus formation capacity. Plant regenerating genotypes were IL3, IL38, IL15, IL1, Hudiba-2 and Mojtamaa-45. Inbred line IL3 was the most regenerable genotype with a shoot formation frequency of 76% averaging 6 shoots per callus. The highest regenerating variety was Mojtamaa-45, which averaged 5 shoots per callus.